Electrically-heated sad-iron.



G. A. SHALER. ELEGTRIGALLY HEATED SAD IRON.

APPLICATION FILED IEIBJZ, 1912.

- Patented NOVA, 1913.

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l/vmeooeo U. A. SEALER. BLBGTRIGALLY HEATED SAD IRON. APPLICATION FILED rmmz, 1912.

Patented Nov. 4, 1913.

2 SHEETS-SHEET 2.

61 Noun? CLARENCE, A. SEALER, 0F WAUPUN, WISCONSIN.

ELECTRICALLY-HEA'IED SAD-IRON.

Specification of Letters Patent.

Patented l\' ov. 4, 191 3.

Application filed February 12, 1812. Serial No. 677,073.

To all whom it may concern:

Be it known that I, CLARENCE A. SHALER, a citizen of the United States, residing at lVaupun, county of Dodge, and State of \Visconsin, have invented new and useful Improvements in Electrically-Heated Sadl'rons, of which the following is "a specification.

My invention relates to improvements in electrically heated sad irons.

The objects of my invention are to provide efficient means for automatically controlling the heat of the sad iron, and to avoid the destructive arcing, which results when it is attempted to regulate the heat by making andbreaking the electrical circuit.

In the following description, reference is had to the accompanying drawings, in which Figure 1 is a central longitudinal sectional view of a sad iron embodying my invention. Fig. 2 is a plan view of the same with the shell removed, and portions of the remaining parts broken away on one side to expose the base and heat controlling thermostat. Fig. 3 is a circuit diagram. Fig. 4 is a rear view of the base portion. Fig. 5 is a circuit diagram, showing a modification of the circuits, and showing the mounting of the, thermostat therein, Fig. 6 is a detail view of the eccentric adjuster.

Like parts are identified by the same reforence characters throughout the several views.

My improved sad iron is constructed with a base member, a heating coil thereon cov-' ered by a heat storing slug and inclosed by a shell, or cap, the margins of which rest upon the base. The handle is secured to the cap member. A thermostat is mounted in a recess in the base and regulates the current .in the heating coils without breaking the circuit. The heat of the upper portion of a sad iron will vary materially independently of the base portion, which,being composed of a comparatively heavy body of iron, chan es temperature more slowly, and I have iscovered that efficient control of the heat can be secured only by locating the thermostat in such relation to the base that it will not be subject to internal or external air cur-' rents to any material extent. By providing a recess in the base of proper size to receive the thermostat, I am enabled to cover it with heat insulating material, and thus not only rotect it from air currents, but e p e i directly to heat from the base at the sides and bottom of the recess without having it exposed directly to heat radiating from the heater. I am therefore able to provide a thermostat which will accurately respond to changes in the temperature of the base of the sad iron, but will not be afiected by those changes of temperature in the upper portion which do not materially affect the base.

Another feature of my improved structure is that of providing means for adjusting the thermostat which will not be easily accessible to the ordinary user, who is not sufficiently skilled to, adjust it properly. I am therefore enabled to adjust the thermostat accurately at the factory with reasonable certainty that such adjustment will be retained in use.

In the drawing, 1 is the base portion of my improved sad iron, the same comprising a Hat plate of metal provided with a recess 2 in which a pair of circuit closing bars 3 and 4 are mounted, their inner ends being secured to supporting insulating blocks 5 and their outer ends being provided with electrodes 6 adapted for mutual con tact. The bar 3 is thermostatic, the same being a compound bar comprising two members of different materials expanding unequally to produce lateral fiexion in a well known manner. The bars 3 and 4 are supported in a flexible box 10and are insulated from each other and from said box 10 by strips of mica, or other insulating material 11. Clamping screws 12 pass through the side of the base 1 With their inner ends bearing against the outer side of the box 10 near its respective ends. These screws are of such length that their outer ends are received in the threaded apertures in the base, which apertures are of such small diameter that the ordinary house-holder will have no tool small enough to enter them and engage these screws. These screws are employed to press the box 10 against a rounded bearingwall 14 on the opposite side of the box, and by turning one screw in one direction and the other screw in the. other direction, the box 10 may beslightly tilted upon the hearing 14. In this manner, the free ends of the bars 3 and 4- at which the electrodes are located, may be swung .to a proper pos1't1on in the recess 2 of the base.

An adjustment of the thermostat 15 secured by a wedge member 15. The thin edge of this wedge member 15 extends between the inner end of an adjusting screw 17 and the outer side of the bar 4 at a point opposite the electrode 6 thereon. This wedge member 15 is actuated by a rod 18, which is connected with the Wedge bar 15 by an eccentric member 19 and crank pin 20, the inner or thicker end of the wedge bar 15 being hung upon this crank pin and the eccentric being mounted upon the rod 18. The screw 1? may be turned inwardly to secure an exact. adjustment of the thermostat by bringing the electrodes 6 into approximate contact, but a further adjustment may then be secured by turning the rod 18 to move the wedge member l5 along the inner end of the screw 17. A set screw 21 serves as a stop to limit the oscillation of rod 18, thus allowing readjustment-s within a limited range.

The bars 3 and 4 constitute terminals for a plurality of electrical circuits through the heater 25. The bar 4 will therefore be insulated from the wedge member 15. The heater 25 is composed of a plurality of coils embedded in a suitable heat distributing material. These coils may be connected, either in series or in parallel. In Fig. 3 I have illustrated them in series connection, and in Fig. 5 they are shown connected in parallel. Referring to Fig. 3, it will be observed that the circuit may be established from the binding post 27 through primary coil 28, thermostatic bar 3-,'the electrodes 6, terminal bar 4, line 29 and binding post 30. When the heat reaches the predetermined point, the flexion of thermostatic bar 3 causes the electrodes 6 to separate, whereupon the circuit will not be broken, but will be established through coil 28 and coil 31 to binding post 80. The additional resistance thus interposed in the circuit by coil 31, reduces the volume of current and thus reduces the temperature. Referring to Fig. 5, however, it will be observed that the main circuit may be established from binding post 27 through a coil 35 to binding post 30 independently of the thermostat. When the electrodes 6 of the thermostat are in contact, however, an additional auxiliary circuit will be established from binding post 17 through coil 37, thermostatic bar 8, electrode 6, terminal bar4 and line 38 to binding post 30. When the two coils illustrated in Fig. 5 are simultaneously in circuit, the volume of the current will of course be greater than it will after the heat-has reached such a degree as to cause a separation of the electrodes 6 by the thermostatic action above explained.

It will of course be understood that the heating coils will be embedded in any suitable heat distributing material. The coils and the material in which they are embedded form a flat member, which rests upon the base 1 and covers the thermostat exposed by extending the recess inclosing shell,

recess, one or more strips of heat insulating material 40 being preferably interposed. heat storing slug 41 is preferably mounted upon the heater and covered with asbestos, or other suitable heat insulating material 42. The slug is connected with the base by marginal screws 43 and the shell is connected with the slug 41 by a screw 45. All of the parts above described are inclosed by this shell, except the base and the rear ends of the bars 3 and 4, which are preferably 2 to the rear of the base. In this manner, the operation of the thermostat may be observed with a minimum exposure thereof to external temperature influences.

I claim- 1. An electrically heated sad iron comprising the combination with a base and an inclosing shell, of an electrical heater mounted upon the base within the shell and provided with a main heating coil and an auxiliary heating coil, a set of binding posts electrically connected to supply current to said coils, anda thermostat controlling the flow of current through the auxiliary coil, the main coil being in constant circuit connection with the binding posts; said coils being adapted by separate use and association to vary the heating capacity while malntaining a predetermined substantial degree of heat in either relation.

2. An electrically heated sad iron comprising the combination with a base and an of an electrical heater mounted upon the base within the shell and provlded with a plurality of heating coils, a set of binding posts electrically connected to supply current to said coils, and a thermostat controlling the flow of current through one of said coils and the other of said coils being in constant circuit connec tion with the binding posts, said thermostat being mounted in a recess in said base, the side and bottom walls of which recess are in proximity to the thermostat.

3. An electrically heated sad iron comprising the combination with a base and an inclosing shell, of an electrical heater mounted upon the base within the shell and provided with a plurality of heating coils, a set of binding posts electrically connected to supply current to said coils, and a thermostat controlling the flow of current through one of said coils and the other of said coils being in constant circuit connection with the binding posts, said thermostat being mounted in a recess in said base, the side and bottom walls of which recess are in proximity to the thermostat, and said recess and thermostat being covered by non heat conducting materiah 4. An electrically heated .sad iron comprising the combination with a recessed base and an inclosing shell, of an electric current to the heater, said t heater within said shell and a thermostat in the base recess regulati the supply of ermostat comprising a terminal bar and a thermostatic bar, each adapted to be included in the circuit with said heater, contact electrodes mo nted upon said bars, an adjustable bearing screw and an adjustable wedge interposed between said bearing screw and the terminal bar, whereby the movement of the wedge may adjust said terminal bar into greater or less proximity to the thermostatic bar. 7

5. An electrically heated sad iron, com-- prising the combination of a base, rovided with a recess, a heating coil, a she inclosing the heating coil, and covering the recess in the base, and a thermostat mounted in said recess and controlling the supply of current to said heating coil, said recess being covered by heat insulating material,

whereby it is protected against direct heat from the heater and exposed to heat from the base at the sides and bottom of said recess.

6. An electrically heated sad iron, comprising the combinati n of a base, rovided with a recess, a heating coil, a shel inclosing the heating coil, and covering the recess in the base, and a thermostat mounted in said recess and controlling the supply of current to said heatin coil, said recess having its bottom and si e walls in close proximity to the thermostat and said base being covered over said recess with non-heat conducting material adapted to protect the thermostat against direct heat radiation from saidheater.

In testimony whereof I afiix my signature in the presence of two witnesses. CLARENCE A. SHALER. Witnesses:

Lnvnnn'rr 0. WHEELER, I. D. Bmumm. 

